U.S. Government Takes Action Against New World Screwworm Threat

On August 19, 2025, the U.S. Department of Health and Human Services (HHS) issued a declaration allowing the Food and Drug Administration (FDA) to grant Emergency Use Authorizations (EUAs) for animal drugs aimed at treating or preventing infestations caused by the New World screwworm (NWS). This parasitic pest, which infests warm-blooded animals including livestock, pets, and wildlife, poses a significant threat to animal health and the U.S. food supply chain. Although the risk to human health remains low, the potential impact on agriculture and national security necessitates proactive measures.

HHS to allow emergency use authorization for animal drugs to fight NWSRTTNewsHHS Allows FDA Emergency Use of Animal Drugs to Combat New World Screwworm, Protect U.S. Food SupplyUnited Press International (UPI)HHS Grants FDA Emergency Authority to Use Animal Drugs Against New World Screwwormdvm360UsNews and World ReportRFD-TV

The New World screwworm was eradicated from North America and Central America decades ago but has been advancing north since 2022, now nearing the U.S.-Mexico border. The FDA has noted that there are currently no FDA-approved drugs for treating NWS in the United States, prompting the need for swift action to mitigate the threat.

HHS Grants FDA Emergency Authority to Use Animal Drugs Against New World Screwworm

HHS Secretary Robert F. Kennedy Jr. emphasized the urgency of the situation, stating, “Today, we are taking decisive action to safeguard the nation’s food supply from this emerging threat.” He added that the authorization equips the FDA to act quickly to limit the spread of NWS and protect livestock. FDA Commissioner Dr. Marty Makary echoed this sentiment, highlighting the agency's commitment to ensuring the necessary tools are available to prevent and control NWS.

HHS Allows FDA Emergency Use of Animal Drugs to Combat New World Screwworm, Protect U.S. Food Supply

Agriculture Secretary Brooke Rollins described the emergency authorization as a critical tool in the fight against NWS, asserting that stopping this pest is a national security priority. “Our cattle ranchers and livestock producers are relying on the Trump administration to defend their livelihoods,” she stated.

Trump Admin Moves to Protect Livestock From Screwworm InfestationRFD-TVHHS Allows FDA Emergency Use of Animal Drugs to Combat New World Screwworm, Protect U.S. Food SupplyR-CALF USA Applauds Further Actions to Combat New World Screwworm; Border Must Remain ClosedHHS Grants FDA Emergency Authority to Use Animal Drugs Against New World ScrewwormUnited Press International (UPI)UsNews and World ReportRTTNews

The New World screwworm, scientifically known as Cochliomyia hominivorax, lays its eggs in open wounds of animals, leading to severe tissue damage and, in some cases, death. The pest has been detected in Mexico, approximately 370 miles from the U.S. border, prompting the USDA to halt imports of Mexican cattle. The USDA is also investing $750 million to build a sterile fly production facility in Texas to combat the screwworm's spread.

USDA’s $750 Million Plan to Keep New World Screwworm Out of the US

While the emergency measures have garnered support from agricultural stakeholders, some critics argue that the reliance on emergency authorizations for unapproved drugs may not be a sustainable long-term solution. R-CALF USA, a cattle producers' group, has called for the southern border to remain closed until Mexico can demonstrate that the pest has been eradicated, emphasizing the need for stringent measures to protect American ranchers.

R-CALF USA Applauds Further Actions to Combat New World Screwworm; Border Must Remain Closed

The FDA is currently assessing existing animal drugs approved for other uses to determine their effectiveness against NWS. Additionally, the USDA plans to enhance surveillance efforts along the U.S.-Mexico border and collaborate with Mexican authorities to restrict animal movement and support containment efforts.

HHS Allows FDA Emergency Use of Animal Drugs to Combat New World Screwworm, Protect U.S. Food Supply

• “Today, we are taking decisive action to safeguard the nation’s food supply from this emerging threat,” — Robert F. Kennedy Jr., HHS Secretary

HHS Allows FDA Emergency Use of Animal Drugs to Combat New World Screwworm, Protect U.S. Food Supply

• “Our priority is to safeguard both animal health and the nation’s food supply.” — Dr. Marty Makary, FDA Commissioner

Trump Admin Moves to Protect Livestock From Screwworm Infestation